Method and apparatus for forming molds



June 17, 1930. BARTw 1,765,320

METHOD AND APPARATUS FOR FORMING MOLDS Filed Oct. 28. 1926 INVENTOR MMJune 11, 1930 UNITED sures PATENT OFFICE" BLASIUS m'r, OF EAST ORANGE,NEW JERSEY, ASSIGNOR TO BART REILEOTOE (30., ING, OI NEWARK, NEW JERSEY,A CORPORATION OF NEW JERSEY KEI'HOD AND APPARATUS FOR FORMING HOLDSApplication filed October-28, 1923. Serial No. 144,808.

The invention relates in general to an improved method for formin'articlesgby electrol ic deposition and to t e apparatus used in theproduction of articles by following the method herein featured. Thepresent application constitutes a companion case with an applicationfiled under even date entitled Method and ap aratus for forming moldsand articles pro uced' thereby, Serial 'No.

The invention in the form herein selected for specific treatment relatesto a method of formlng working molds for use subsequently in formingflanged metallic parabolic reflec- 1 tors, but it is understood thatthis use is simply illustrative of the adaptability of the invention tothe electroforming of any nonplanar article particularly those in whichthere are deep recesses. Difliculty has been experienced heretofore inproviding a umform thickness of deposit across such recessed surfacesdue presumably to the fact that the depositing current escapes by theshortest pathbefore it can reach the deep port ons of the recess. It isknown that the deposit is of greater thickness adjacent the anodeandthat the deposit thins out towards the lowest portion of the recessedparts of the surface of the mold under treatment.

The primary object of the invention 1s to provide a mode of treatmentand an assembliyl of the parts in the electrolytic bath 1n sue way as toinsure a uniformity of deposition over surfaces which contain deeplyrecessed arts.

P This phase of the invention is attained in two ways and which arepreferably used conjointly to obtain themost satisfactory results. Bythe first method, the anode, preferis positioned in close proxlmityto,but not touching the mold surface under treatment and in general thefirst method features the disposing of the anode so that the distancebetween the same and the opposite surface of the mold will besubstantially uniform.

The second method is to cause, the electrolyte to flow across thedepressed surfaces and preferably to extend through the deepest por- 5tion of the recessed surface.

ably in-the form of fine nuggets or particles,

.. With reference to the apparatus feature of the disclosure. theprimary object is to provide a simplified form of structural parts forlocating the anode material in close proximity to the non-planar surfaceof the mold, and to provide in connection with the mold holder uidconducts which will insure the movement of the electrolyte past all ofthe mold surface under treatment and in such wa .as will tend to insureuniformity of electro ytic deposition.

, Another object of the invention is to provide an anode containingbasket the underside or bottom of which will conform substantially tothe configuration of the mold surface under treatment, which basket canbe readily secured to-the mold sup ort, and with the anode materialtherein, will tend to provide the requisite location of the anodematerial and the insurance of a positive contact between the currentcarrying anode bar and the anode material in the basket.

Various other objects and advantages of the invention will be obviousfrom a consideration ofthe preferred method of racticing the inventionhereinafter describe and from an inspection of the accompanying drawingsand in part will be more fully set forth in the following particulardescription of one method and of one form of apparatus for practicingthe method and the invention also consists in certain new and noveloperations and features of construction and combination of partshereinafter set forth and claimed.

In the accompanying drawing, the figure is a view largely in sideelevation and artly in radial section of a mold supporting frame, withan anode basket positioned thereon together constituting a preferredembodiment of the apparatus feature of the disclosure and illustrating astep in the method featureof the disclosure.

In the drawing, there is shown a metal master mold 10-0n the outstandingflange 11 of which is positioned a celluloid-ring 12 designedsubsequently to constitute a part of a finished article and which in theinstant case is a working mold 13. The master mold and ring arecontained in a celluloid clamping frame 14, all as is more particularlydisclosed in the above identified copending ap lication. The presentdisclosure distinguls es from the companion application in that thecellu loid nipple 16 which acts to block off the deposition of metalforming on the metal connecting tip is provided centrally thereof withan opening 16 for ermltting the passage of the electrolyte t erethroughas will hereinafter be more fully described. In this case negativeelectric connection is made to the metal mold through a conducting strip17 which mayalso be utilized for the purpose of sus ending theassemblage in an electrolytic bat and for this purpose is provided withan 15 eye 18 for engagement "with the buss bars usually positioned overthe electrolytic tank. The resent disblosure features the use of an anoe basket 19, formed of insulating material, preferably celluloid. Thebottom 20 20 of the basket is provided with perforations 21 and isdesigned so as to conform at least substantially to the configuration ofthe metal mold surface under treatment. In the case 6f the arabolic formof metal surface herein disc osed, the bottom of the basket is ofsimilar parabolic formation and 1s outllned by flanged portion 22 whichoverlaps the flanged portion 11 of the mold. The basket 1s provided withan outstanding attaching flange 3o 23, demountably secure in position yclampin screws 24. The basket is provided within t e line of clampingscrews with an upstanding wall 25 so as to insure suflicient capacit tocontain the requisite amount of anode orm'mg material 26 'eontained inthe basket. For instance, if it is intended to elect-roplate the moldwith copper the material 26 is granularcopper, and in any case the anodematerial is of sufiicient fineness of particles to insure aconfiguration of the underside of the anode which will correspond, atleast roughly, to the configuration of the mold surface under treatment.'Preferably, the loose anode material is arched out of the baskettowards the center so as to insure an extensive electric contact withthe positive current carrying anode bar 31. The anode bar is preferablya metal cylinder to which electric current is led thr ough the flexibleconnector 27 leading to the bindin screw 28 engaging bar 31. A celluloidtubmg 29 extends through the bar 31 and has its lower discharge endintruded into the anode material adjacent the bottom thereof and inaxial alignment with the opening 16 in the outlet nipple 16'.

In operation, the electrolyte is forced under pressure or is permittedto flow through the tubing 29, through the anode material which causesthe liquid to spread across the entire bottom of the basket, with someof the electrode discharging through the lowermost portion of the recessin the mold and out through the aperture 16.

It is, of course, within the scope of the disclosure to position theentire device illustrated withln and beneath the surface of anelectrolytic bath either with or without the current forming tubing 29and outlet 16.

B means of the device illustrated and following the method hereinsuggested it is possible to form the coatings or layers on the mold ofsubstantially uniform thickness, and there is thereby avoided thepossibility of abnormal formation of trees and other growths whichusually take place adjacent the celluloid ring.

' While I have shown and described, and have pointed out in the annexedclaims, certain novel features of my invention, it will be understoodthat various omissions, substitutions and changes in the form anddetails of the device illustrated and in its operation may I be made bythose skilled in the art without departing from the spirit of theinvention.

Havipg thus described my invention, I claim:

-1. In the art of electroplating the recessed portion of a surface, themethod which consists in positioning the depositing metal in solid formwithin the recess, adjacent to but not in contact with the surface ofthe recess r to be plated, and in fixed relation thereto, and subjectingthe same to the action of an electrolytic bath while causing theelectrolyte to flow through the solid metal and into depositing contactwith the recessed surface.

t 2. In the art of electroforming articles having irregular surfaces,the method which consists in disposing anode forming material injuxtaposition to the negative mold surface to be coated, arranging suchmaterial so that the distances between the same and the opposing surfaceof the mold shall be substantially uniform, subjecting the mold andanode material so disposed to the action of an electrolytic bath whilecausing the electro-. lytiidto flow across the deepest part of the mosurfaces, the method which consists in subjecting the concaved surfaceto the action of an electrolyte bath while causing the electrolyte toflow through the deepest portion of the concaved surface.

4. In the art of electroplating irregular surfaces, the method whichconsists in disposing an anode of metallic particles of theelectroplating material in juxtaposition tothe surface to be plated andspaced substantially equidistantly therefrom, and subjecting the surfacetogether with the anode particles to the action of a circulatingelectrolytic bath.

5. In the art of electroplating irregular surfaces, the method whichconsists in disposing an anode of metallic particles of theelectroplating material in juxtaposition to the surface to be plated andspaced substantially equidistantly therefrom, and subjecting the surfacetogether with the anode par- 3. In the art of electroplating concaved noticles to the action of an electrolytic bath while causing a stream ofthe electrolyte to move past the anode particles and into depositingengagement with the irregular surface being plated.

. 6. In a device for use informing working molds for subsequent use informing flanged parabolic reflectors, the combination of a mefsipacedsubstantially a relative thereto, and means particles in tallic masterform including a parabolic central portionv ro'vided with an outstandingflange, said ange having a ring locating groove in one face, a ringlocated by said groove, a ring shaped clamp for securing the ringtemporarily to the mold, an anode basket carried by the frame and havinga perforated bottom conforming'somewhat to and equidistant from the n'geand parabolic portion of the master mold, said basket adapted tocontainparticles of metal forming an anode positioned by said basketsubstantially equidistant from the mold surface to be plated.

In a device for use in forming working molds for subsequent parabolicreflectors, metallic master form the combination of a including aparabolic central portion provided with an outstanding flange, saidflange having a ring locating groove in one face, a ring located by saidgroove, a ring shaped clamp for securing the ring temporarily to themold, an anode basket carried by the frame and having a perforatedbottom conforming somewhat to and spaced substantially equidistant fromthe flange and parabolic portion of the master mold, said basket adaptedto contain particles of metal forming an anode positioned by said basketsubstantially equidistant from the mold surface to be plated, and ahollow anodetube adapted, to be intruded into the particles in thebasket and adapted to convey electrolyte to the basket. I

8. In a device of the classdescribed, the combination of a metal facedmold having a depression in the face to be i electroplated, means forpositionin a body of metal anode particles substantial y equidistantlyspaced from the surface of said depression, and fixed for conveying astream of electrolyte through the depression surface.

9 Ina device of the class described, the combination of a metal facedmold having a depression in the face to be electroplated, means forpositioning a body of metal anode fixed relationsubstantiallyeqmdistantly spaced from the surface of said de pressionand a conduit for directing a flow of electrolyte through saidparticles.

10. In a device for electroplatirfg irregular surfaces including a formhaving the irregular configuration of the desired surface, anv

use'in forming flanged,

the particles to basket of insulating material with its bottomperforated and conforming somewhat to the configuration of said surface,closely positioned to but spaced therefrom and adapted to contain ananode material and to position the same close to the concaved surface tobe plated, and an anode substantially centered in said basket, and atube for conducting electrolyte to the particles in the basket.

In a device for electroplating concaved surfaces, the combination ofananode basket of insulating material with its bottom perforated andconforming somewhat to the configuration of said surface, closelypositioned to but spaced therefrom tain'an anode material and toposition the same close to the concaved surface to be plated, and ananode substantially centered in said basket. 1

13. In a device for electroplating concaved surfaces, the combination ofan anode basket of insulating material with its bottom perforated andconforming somewhat to the configuration of said surface, closelypositioned to but spaced therefrom and adapted to contain within thebasket and above the bottom thereof an anode material and to positionthe same close to and above the concaved surface to be plated.

14; In a device of the class described, a mold provided with a concavedportion, and having an opening located at the lowest part of saidconcaved portion to provide an electrolyte opening to permit the passageof electrolyte through the concaved part of the mold when installed inan electrolytic bath.

- 15. In a device of the class described, the combination of a moldprovided with a concaved portion, and having an opening located at thelowest part of said concaved portion to provide an electrolyte openingto permit the passage of electrolyte through the concaved part of themold when installed in an electrolytic bath, anda tln'mble of insulatingI material outlining said opening.

16. A metal mold provided with an opening extending therethrough, ametal connector inserted in said opening and providmg means for ma gelectric connection with the metal mold. 17. A metal mold ing extendingtherethrough, a metal connector inserted in said opening and providingprovided with an openand adapted to conmeans for making electricconnection with means for metal conthe metal mold, and insulatinstopping off the deposition on said nector.

18'. In a device of the class described, the combination of a mold, aring detachably located on the mold, means'for clamping the ring to themold and means for locating an anode in substantially equidistantly saeexi relation to the portion of the mold out eci by the ring. i I

19. In a device of the class described, the combination of a mold havingan irregular surface and an anode holder having its bottom perforatedand disposed for locating solid anode particles in substantiallyequidistantly spaced relation above said surface of the mold. Signed atNew York, in the county of New York and State of New York, this 20th dayof October, A. D. 1926.

v BLASIUS BART.

